{{AUR|Profile-sync-daemon}} (psd) is a tiny pseudo-daemon designed to manage browser profile(s) in tmpfs and to periodically sync back to the physical disc (HDD/SSD). This is accomplished by an innovative use of rsync to maintain synchronization between a tmpfs copy and media-bound backup of the browser profile(s). Additionally, psd features several crash recovery features.

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{{Article summary text|{{AUR|Profile-sync-daemon}} (psd) is a tiny shell script designed to manage your browser's profile in tmpfs and to periodically sync it back to your physical disc (HDD/SSD). This is accomplished via a symlinking step and an innovative use of rsync to maintain back-up and synchronization between the two. One of the major design goals of psd is a completely transparent user experience.}}

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{{Article summary heading|Related}}

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{{Article summary wiki|Anything-sync-daemon}}

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{{Article summary wiki|Firefox}}

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{{Article summary wiki|Chromium}}

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{{Article summary wiki|Opera}}

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{{Article summary wiki|SSD}}

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{{Article summary end}}

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== Benefits of Psd ==

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{{Note|Occasionally, updates/changes are made to the default config file {{ic|/usr/share/psd/psd.conf}} upstream. The user copy {{ic|$XDG_CONFIG_HOME/psd/psd.conf}} will need to be diffed against it. On Arch Linux, pacman should notify the user to do this. Users of other package managers and/or distros will need to periodically diff the files manually.}}

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Running this daemon is beneficial for two reasons:

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#Reduced wear to physical discs

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{{Note|Sometimes this daemon can slow down your login, because it copy all your browser cache to the RAM at [https://www.reddit.com/r/archlinux/comments/4l7gvm/very_slow_when_login/d3lrx9y/ login]. }}

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== Design goals and benefits of psd ==

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#Transparent user experience

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#Reduced wear to physical drives

#Speed

#Speed

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Since the profile(s), browser cache, etc. are relocated into tmpfs, the corresponding onslaught of I/O associated with using the browser is also redirected from the physical disc to RAM, thus reducing wear to the physical disc and also greatly improving browser speed and responsiveness. The access time of RAM is on the order of nanoseconds while the access time of physical discs is on the order of milliseconds. This is a difference of six orders of magnitude or 1,000,000 times faster.

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Since the profile(s), browser cache*, etc. are relocated into [[tmpfs]] (RAM disk), the corresponding I/O associated with using the browser is also redirected from the physical drive to RAM, thus reducing wear to the physical drive and also greatly improving browser speed and responsiveness.

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==Supported Browsers and Caveats==

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{{Note|Some browsers such as Chrome/Chromium, Firefox (since v21) and Midori actually keep their cache directories '''separately''' from their profile directory. It is not within the scope of profile-sync-daemon to modify this behavior; users are encouraged to refer to the [[Chromium tweaks#Cache in tmpfs]] section for Chromium and to the [[Firefox on RAM]] article for several workarounds.}}

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Currently, the following browsers are auto-detected and managed:

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#[[Chromium]]

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#[[Firefox]]

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#{{AUR|google-chrome}}

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#[[Midori]]

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#[[Opera]]

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#{{AUR|Opera-next}}

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{{Note|Chromium actually keeps its cache directory '''separately''' from its browser profile directory. It is not within the scope of profile-sync-daemon to modify this behavior; users are encouraged to refer to the [[Chromium_Tips_and_Tweaks#Cache_in_tmpfs]] section of the main [[Chromium_Tips_and_Tweaks]] article for several work-arounds.}}

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== Setup and installation ==

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[[Install]] the {{AUR|profile-sync-daemon}} package.

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==Setup and Installation==

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=== Edit the config file ===

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{{AUR|Profile-sync-daemon}} is available for download from the [[Arch User Repository|AUR]]. Build it and install like any other package.

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Run psd the first time which will create {{ic|$XDG_CONFIG_HOME/psd/psd.conf}} (referred to hereafter as as the config file) which contains all settings.

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=== Edit /etc/psd.conf ===

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{{Note|Any edits made to this file while psd is active will be applied only after psd has been restarted from the systemd user service.}}

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Edit the included {{ic|/etc/psd.conf}} defining which user(s) will have their profiles managed by psd.

First time running psd so please edit /home/facade/.config/psd/psd.conf to your liking and run again.

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# and sync'ed to tmpfs.

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# Do NOT list a user twice!

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USERS="bar foo"

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{{Note|At least one user must be defined.}}

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* Optionally enable the use of overlayfs to improve sync speed and to use a smaller memory footprint. Do this in the USE_OVERLAYFS variable. The user will require sudo rights to {{ic|/usr/bin/psd-overlay-helper}} to use this option and the kernel must support overlayfs version 22 or higher. See the FAQ below for additional details.

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* Optionally define which browsers are to be managed in the BROWSERS array. If none are defined, the default is all detected browsers.

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* Optionally disable the use of crash-recovery snapshots (not recommended). Do this in the USE_BACKUPS variable.

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* Optionally define the number of crash-recovery snapshots to keep. Do this in the BACKUP_LIMIT variable.

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Optionally uncomment the BROWSERS array and populate it with whichever browser(s) are to be sync'ed to tmpfs. If the BROWSERS array stays commented (default) then all supported browsers will be sync'ed.

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Example: Let's say that Chromium, Opera and Midori are installed but only Chromium and Opera are to be sync'ed to tmpfs since the user keeps Midori as a backup browser and it is seldom used:

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Example: Let's say that both chromium and mirdori are installed but only chromium is to be sync'ed to tmpfs since the user keeps Midori as a backup browser and it is seldom used:

# List browsers separated by spaces to include in the sync. Useful if you do not

# List browsers separated by spaces to include in the sync. Useful if you do not

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# wish to have all possible browser profiles sync'ed.

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# wish to have all possible browser profiles sync'ed which is the default if

# If the following is commented out (default), then all available/supported

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BROWSERS="chromium opera"

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# browsers will be sync'ed

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BROWSERS="chromium"

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Beginning with version 5.54 of psd, native support for [[#What is_overlayfs_mode?|overlayfs]] is included. This feature requires at least a Linux kernel version of 3.18.0 or greater.

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== Supported browsers ==

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Currently, the following browsers are auto-detected and managed:

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* [[Chromium]]

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* {{AUR|chromium-dev}}

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* {{AUR|conkeror-git}}

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* [[Epiphany]]

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* [[Firefox]] (all flavors including stable, beta, and nightly)

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* {{AUR|google-chrome}}

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* {{AUR|google-chrome-beta}}

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* {{AUR|google-chrome-dev}}

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* [https://bbs.archlinux.org/viewtopic.php?id=117157 heftig's version of Aurora]: An Arch Linux-only browser

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* {{AUR|icecat}}

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* [[Luakit]]

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* {{AUR|inox}}

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* [[Midori]]

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* [[Opera]]

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* {{AUR|otter-browser}}

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* [[Qutebrowser]]

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* {{AUR|palemoon}} / {{AUR|palemoon-bin}}

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* {{Pkg|qupzilla}}{{Broken package link|replaced by {{Pkg|falkon}}}}

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* {{AUR|rekonq}}

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* {{Pkg|seamonkey}}

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* {{Pkg|surf}}

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* {{AUR|vivaldi}}

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== Using psd ==

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Optionally redefine the location of the tmpfs mount to use for syncs. Do this in the VOLATILE variable. Note that for Arch Linux, the default value of "/tmp" should work just fine.

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=== Preview (parse) mode ===

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=== Using psd ===

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The 'parse' option can be called to show users exactly what ''psd'' will do/is doing based on {{ic|$XDG_CONFIG_HOME/psd/psd.conf}} as well printout useful information such as profile size, paths, and if any recovery snapshots have been created.

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The initial synchronization will occur when the daemon starts. Additionally, cron (if running) will call it to ''sync'' or update once per hour. Finally, psd will sync back a final time when it is called to stop.

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$ psd p

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Profile-sync-daemon v6.03 on Arch Linux.

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Systemd service is currently active.

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Systemd resync service is currently active.

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Overlayfs v23 is currently active.

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Psd will manage the following per /home/facade/.config/psd/psd.conf settings:

As shown in the output and as stated above, if no specific browser or subset of browsers are defined in the BROWSERS array, ''psd'' will sync ALL supported profiles that it finds for the given user(s).

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Call the daemon to start, stop, or sync (restart) like any standard Arch daemon:

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=== Clean mode ===

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# rc.d <command> psd

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The clean mode will delete ALL recovery snapshots that have accumulated. Run this only if you are sure that you want to delete them.

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It is ''highly'' recommended to start/stop the daemon at boot/shutdown. This is accomplished by adding '''psd''' to the DAEMONS array in {{ic|/etc/rc.conf}} like so:

Users making use of [[Systemd]] may manage the service using the '''systemctl''' command. Start/stop the service using:

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With the release of the version 6.x series of psd, the only init system that is officially supported is systemd. Psd ships with a systemd user service to start or stop it (psd.service). Additionally, a provided resync-timer will run an hourly resync from tmpfs back to the disk. The resync-timer is started automatically with psd.service so there is no need to attempt to start the timer.

For users unfamiliar with systemd user mode, use the following commands to enable the psd service:

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# systemctl enable psd.service

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=== Sync at More Frequent Intervals (Optional) ===

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$ systemctl --user [option] psd.service

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{{Note|This step is NOT required. '''psd''' will update once per hour on its own.}}

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Available options are {{Ic|start}}, {{Ic|stop}}, {{Ic|enable}}, {{Ic|disable}} and {{Ic|status}}.

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Users wishing to have syncs occur more frequently can simply add a line to the root crontab to call the ''sync'' function of psd like so:

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===Supported distros===

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Since psd is just a bash script with a systemd service, it should run on any flavor of Linux running systemd. Around a dozen distros provide an official package or user-maintained option to install psd. One can also build psd from source. See the official website for available packages and installation instructions.

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# crontab -e

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=== Sync at more frequent intervals (optional) ===

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The package provided re-sync timer triggers once per hour. Users may optionally redefine this behavior simply by [[Systemd#Editing provided units|extending the systemd unit]]. The example below changes the timer to sync once every ten minutes:

{{Note|There are several versions of overlayfs available to the Linux kernel in production in various distros. Versions 22 and lower have a module called 'overlayfs' while newer versions (23 and higher) have a module called 'overlay' -- note the lack of the 'fs' in the newer version. Psd will automatically detect the overlayfs available to your kernel if it is configured to use one of them.}}

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Overlayfs is a simple union file-system mainlined in the Linux kernel version 3.18.0. Starting with psd version 5.54, overlayfs can be used to reduce the memory footprint of psd's tmpfs space and to speed up sync and unsync operations. The magic is in how the overlay mount only writes out data that has changed rather than the entire profile. The same recovery features psd uses in its default mode are also active when running in overlayfs mode. Overlayfs mode is enabled by uncommenting the ''USE_OVERLAYFS="yes''" line in {{ic|$XDG_CONFIG_HOME/psd/psd.conf}} followed by a [[restart]] of the daemon.

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Since version 6.05 of psd, users wanting to take advantage of this mode MUST have [[sudo]] rights (without password prompt) to {{ic|/usr/bin/psd-overlay-helper}} or global sudo rights. The following line in {{ic|/etc/sudoers}} will supply an [[user]] with these rights. Add it using [[Sudo#Using_visudo|visudo]]:

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user ALL=(ALL) NOPASSWD: /usr/bin/psd-overlay-helper

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See the example in the PREVIEW MODE section above which shows a system using overlayfs to illustrate the memory savings that can be achieved. Note the "overlayfs size" report compared to the total "profile size" report for each profile. Be aware that these numbers will change depending on how much data is written to the profile, but in common use cases the overlayfs size will always be less than the profile size.

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=== I need more memory to accommodate my profile/profiles in /run/user/xxxx. How can I allocate more? ===

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The standard way of controlling the size of /run/user is the RuntimeDirectorySize directive in {{ic|/etc/systemd/logind.conf}} (see the man page for logind.conf for more). By default, 10% of physical memory is used but one can increase it safely. Remember that tmpfs only consumes what is actually used; the number specified here is just a maximum allowed.

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=== Why do I have another browser profile directory "foo-back-ovfs" when I enable overlayfs? ===

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The way overlayfs works is to mount a read-only base copy (so-called lower dir) of the profile, and manage the new data on top of that. In order to avoid resyncing to the read-only file system, a copy is used instead. So using overlayfs is a trade off: faster initial sync times and less memory usage vs. disk space in the home dir.

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=== My system crashed and did not sync back. What do I do? ===

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Odds are the "last good" backup of your browser profiles is just fine still sitting happily on your filesystem. Upon restarting {{ic|psd}} (on a reboot for example), a check is performed to see if the symlink to the tmpfs copy of your profile is invalid. If it is invalid, ''psd'' will snapshot the "last good" backup before it rotates it back into place. This is more for a sanity check that ''psd'' did no harm and that any data loss was a function of something else.

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{{Note|Users can disable the snapshot/backup feature entirely by uncommenting and setting the USE_BACKUPS variable to 'no' in {{ic|$XDG_CONFIG_HOME/psd/psd.conf}} if desired.}}

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=== Where can I find this snapshot? ===

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It depends on the browser. You will find the snapshot in the same directory as the browser profile and it will contain a date-time-stamp that corresponds to the time at which the recovery took place. For example, chromium will be {{ic|~/.config/chromium-backup-crashrecovery-20130912_153310}} -- of course, the date_time suffix will be different for you.

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=== How can I restore the snapshot? ===

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* Stop {{ic|psd}}.

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* Confirm that there is no symlink to the tmpfs browser profile directory. If there is, ''psd'' did not stop correctly for other reasons.

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* Move the "bad" copy of the profile to a backup (do not blindly delete anything).

At this point you can launch chromium which will use the backup snapshot you just copied into place. If all is well, close the browser and restart psd. You may safely delete {{ic|~/.config/chromium-backup-crashrecovery-20130912_153310}} at this point.

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=== Can psd delete the snapshots automatically? ===

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Yes, run psd with the "clean" switch to delete snapshots.

== Support ==

== Support ==

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Post in the [https://bbs.archlinux.org/viewtopic.php?pid=1026974 discussion thread] with comments or concerns.

Post in the [https://bbs.archlinux.org/viewtopic.php?pid=1026974 discussion thread] with comments or concerns.

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== psd on other distros ==

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''psd'' is a bash script and should therefore run on any Linux distro. Around a dozen distros provide an official package or user-maintained option to install psd. See the [https://github.com/graysky2/profile-sync-daemon#installation-from-distro-packages official website] for available packages and installation instructions.

Latest revision as of 14:17, 14 March 2018

Profile-sync-daemonAUR (psd) is a tiny pseudo-daemon designed to manage browser profile(s) in tmpfs and to periodically sync back to the physical disc (HDD/SSD). This is accomplished by an innovative use of rsync to maintain synchronization between a tmpfs copy and media-bound backup of the browser profile(s). Additionally, psd features several crash recovery features.

Note: Occasionally, updates/changes are made to the default config file /usr/share/psd/psd.conf upstream. The user copy $XDG_CONFIG_HOME/psd/psd.conf will need to be diffed against it. On Arch Linux, pacman should notify the user to do this. Users of other package managers and/or distros will need to periodically diff the files manually.

Note: Sometimes this daemon can slow down your login, because it copy all your browser cache to the RAM at login.

Design goals and benefits of psd

Transparent user experience

Reduced wear to physical drives

Speed

Since the profile(s), browser cache*, etc. are relocated into tmpfs (RAM disk), the corresponding I/O associated with using the browser is also redirected from the physical drive to RAM, thus reducing wear to the physical drive and also greatly improving browser speed and responsiveness.

Note: Some browsers such as Chrome/Chromium, Firefox (since v21) and Midori actually keep their cache directories separately from their profile directory. It is not within the scope of profile-sync-daemon to modify this behavior; users are encouraged to refer to the Chromium tweaks#Cache in tmpfs section for Chromium and to the Firefox on RAM article for several workarounds.

Setup and installation

Edit the config file

Run psd the first time which will create $XDG_CONFIG_HOME/psd/psd.conf (referred to hereafter as as the config file) which contains all settings.

Note: Any edits made to this file while psd is active will be applied only after psd has been restarted from the systemd user service.

$ psd
First time running psd so please edit /home/facade/.config/psd/psd.conf to your liking and run again.

Optionally enable the use of overlayfs to improve sync speed and to use a smaller memory footprint. Do this in the USE_OVERLAYFS variable. The user will require sudo rights to /usr/bin/psd-overlay-helper to use this option and the kernel must support overlayfs version 22 or higher. See the FAQ below for additional details.

Optionally define which browsers are to be managed in the BROWSERS array. If none are defined, the default is all detected browsers.

Optionally disable the use of crash-recovery snapshots (not recommended). Do this in the USE_BACKUPS variable.

Optionally define the number of crash-recovery snapshots to keep. Do this in the BACKUP_LIMIT variable.

Example: Let's say that Chromium, Opera and Midori are installed but only Chromium and Opera are to be sync'ed to tmpfs since the user keeps Midori as a backup browser and it is seldom used:

Using psd

Preview (parse) mode

The 'parse' option can be called to show users exactly what psd will do/is doing based on $XDG_CONFIG_HOME/psd/psd.conf as well printout useful information such as profile size, paths, and if any recovery snapshots have been created.

Start and stop psd

With the release of the version 6.x series of psd, the only init system that is officially supported is systemd. Psd ships with a systemd user service to start or stop it (psd.service). Additionally, a provided resync-timer will run an hourly resync from tmpfs back to the disk. The resync-timer is started automatically with psd.service so there is no need to attempt to start the timer.

For users unfamiliar with systemd user mode, use the following commands to enable the psd service:

$ systemctl --user [option] psd.service

Available options are start, stop, enable, disable and status.

Supported distros

Since psd is just a bash script with a systemd service, it should run on any flavor of Linux running systemd. Around a dozen distros provide an official package or user-maintained option to install psd. One can also build psd from source. See the official website for available packages and installation instructions.

Sync at more frequent intervals (optional)

The package provided re-sync timer triggers once per hour. Users may optionally redefine this behavior simply by extending the systemd unit. The example below changes the timer to sync once every ten minutes:

FAQ

What is overlayfs mode?

Note: There are several versions of overlayfs available to the Linux kernel in production in various distros. Versions 22 and lower have a module called 'overlayfs' while newer versions (23 and higher) have a module called 'overlay' -- note the lack of the 'fs' in the newer version. Psd will automatically detect the overlayfs available to your kernel if it is configured to use one of them.

Overlayfs is a simple union file-system mainlined in the Linux kernel version 3.18.0. Starting with psd version 5.54, overlayfs can be used to reduce the memory footprint of psd's tmpfs space and to speed up sync and unsync operations. The magic is in how the overlay mount only writes out data that has changed rather than the entire profile. The same recovery features psd uses in its default mode are also active when running in overlayfs mode. Overlayfs mode is enabled by uncommenting the USE_OVERLAYFS="yes" line in $XDG_CONFIG_HOME/psd/psd.conf followed by a restart of the daemon.

Since version 6.05 of psd, users wanting to take advantage of this mode MUST have sudo rights (without password prompt) to /usr/bin/psd-overlay-helper or global sudo rights. The following line in /etc/sudoers will supply an user with these rights. Add it using visudo:

user ALL=(ALL) NOPASSWD: /usr/bin/psd-overlay-helper

See the example in the PREVIEW MODE section above which shows a system using overlayfs to illustrate the memory savings that can be achieved. Note the "overlayfs size" report compared to the total "profile size" report for each profile. Be aware that these numbers will change depending on how much data is written to the profile, but in common use cases the overlayfs size will always be less than the profile size.

I need more memory to accommodate my profile/profiles in /run/user/xxxx. How can I allocate more?

The standard way of controlling the size of /run/user is the RuntimeDirectorySize directive in /etc/systemd/logind.conf (see the man page for logind.conf for more). By default, 10% of physical memory is used but one can increase it safely. Remember that tmpfs only consumes what is actually used; the number specified here is just a maximum allowed.

Why do I have another browser profile directory "foo-back-ovfs" when I enable overlayfs?

The way overlayfs works is to mount a read-only base copy (so-called lower dir) of the profile, and manage the new data on top of that. In order to avoid resyncing to the read-only file system, a copy is used instead. So using overlayfs is a trade off: faster initial sync times and less memory usage vs. disk space in the home dir.

My system crashed and did not sync back. What do I do?

Odds are the "last good" backup of your browser profiles is just fine still sitting happily on your filesystem. Upon restarting psd (on a reboot for example), a check is performed to see if the symlink to the tmpfs copy of your profile is invalid. If it is invalid, psd will snapshot the "last good" backup before it rotates it back into place. This is more for a sanity check that psd did no harm and that any data loss was a function of something else.

Note: Users can disable the snapshot/backup feature entirely by uncommenting and setting the USE_BACKUPS variable to 'no' in $XDG_CONFIG_HOME/psd/psd.conf if desired.

Where can I find this snapshot?

It depends on the browser. You will find the snapshot in the same directory as the browser profile and it will contain a date-time-stamp that corresponds to the time at which the recovery took place. For example, chromium will be ~/.config/chromium-backup-crashrecovery-20130912_153310 -- of course, the date_time suffix will be different for you.

How can I restore the snapshot?

Stop psd.

Confirm that there is no symlink to the tmpfs browser profile directory. If there is, psd did not stop correctly for other reasons.

Move the "bad" copy of the profile to a backup (do not blindly delete anything).

At this point you can launch chromium which will use the backup snapshot you just copied into place. If all is well, close the browser and restart psd. You may safely delete ~/.config/chromium-backup-crashrecovery-20130912_153310 at this point.

Can psd delete the snapshots automatically?

Yes, run psd with the "clean" switch to delete snapshots.

Support

psd on other distros

psd is a bash script and should therefore run on any Linux distro. Around a dozen distros provide an official package or user-maintained option to install psd. See the official website for available packages and installation instructions.